1. Field of the Invention
This invention relates to a printing device, and in particular to a technique for performing printing by forming dots on a print medium while performing main scanning and sub-scanning.
2. Description of the Related Art
In recent years, printing devices that eject ink droplets from nozzles while performing main scanning to form dots on a print medium have come to enjoy widespread use as computer output devices. Dot recording modes employed in such printing devices include “non-overlap print mode” in which dots on each main scan line of printing paper are recorded with ink ejected from a single nozzle, and “overlap print mode” in which dots on each main scan line of printing paper are recorded with ink ejected from two or more nozzles. Additionally, there is a “partial overlap print mode” in which only certain main scan lines are printed in a manner analogous to overlap print mode.
In printing modes that involve main scanning and sub-scanning, recording movement of a given pattern is repeated in the sub-scanning direction. In each pattern movement, the positional relationship in which dots are recorded on each pixel is fixed and the order in which these dots are recorded on pixels is also fixed. The printed pattern resulting from the nozzles employed to record dots on each pixel in combination with the order in which these dots are recorded on pixels is herein referred to as “texture.” If texture repeated in the sub-scanning direction on printing paper is conspicuous, a noticeable stripe pattern will appear in areas that should be filled with a single color, resulting in diminished quality of the printed result.
In view of the aforementioned drawbacks pertaining to the prior art, it is an object of the present invention to provide a technique for reducing degraded quality in printed results due to nozzles employed to record dots on each pixel in combination with the order in which these dots are recorded on pixels.